Tunnels and Underground Spaces in Nuclear Power Plants
As India accelerates its transition toward sustainable energy, nuclear power is emerging as a crucial pillar of low-carbon electricity generation. In this context, the innovative use of tunnels and underground spaces is redefining how nuclear power plants are built and operated—enhancing safety, efficiency, and environmental compatibility. Sandeep Singh Nirmal, Principal Tunnel Engineer at Jacobs, delves into the strategic role these subterranean systems play in the nuclear energy landscape.
Advantages of Nuclear Power and Its Role in Sustainable Energy Transition
Nuclear power plants offer numerous advantages, making them a crucial component in the global transition to sustainable energy. One of the primary benefits is their ability to generate large amounts of electricity with minimal greenhouse gas emissions. Unlike fossil fuels, nuclear energy produces no carbon dioxide during operation, significantly reducing the carbon footprint and helping combat climate change. This clean energy source is vital for countries like India, which are striving to meet their growing energy demands while adhering to international climate commitments.
India, with its ambitious plans to expand nuclear capacity, is a prime example of how nuclear energy can contribute to sustainable development. As of April 2025, India operates 25 nuclear reactors across eight power plants, generating around 3% of the country's total electricity. This contribution is modest compared to countries like France, where nuclear power accounts for about 70% of electricity generation. However, India's commitment to increasing its nuclear capacity aligns with global trends, as nations worldwide recognize the need for reliable, low-carbon energy sources to achieve net-zero emissions by 2050.
The United Nations Sustainable Development Goals (SDGs) provide a framework for addressing global challenges, including energy sustainability. Nuclear power directly supports several SDGs, such as:
SDG 7: Affordable and Clean Energy: Nuclear energy provides a reliable and sustainable source of electricity, contributing to universal access to modern energy services[1].
SDG 13: Climate Action: By reducing greenhouse gas emissions, nuclear power helps mitigate climate change and supports efforts to limit global temperature rise.
SDG 9: Industry, Innovation, and Infrastructure: The development of nuclear power infrastructure promotes technological innovation and sustainable industrialization.
Role of Tunnels and Underground Spaces in Nuclear Power Plants
The construction and operation of nuclear power plants involve extensive use of tunnels and underground spaces. These subterranean structures play a critical role in enhancing the safety, efficiency, and environmental sustainability of nuclear facilities.
Safety and Security
One of the primary reasons for utilizing underground spaces in nuclear power plants is to enhance safety and security. Tunnels and underground spaces provide robust protection against natural disasters, such as earthquakes and tsunamis, as well as potential human threats, including terrorism and sabotage. By housing critical components like reactors, spent fuel pools, and control rooms underground, nuclear plants can significantly reduce the risk of damage and radiation leaks.
Efficient Use of Space
Nuclear power plants require substantial infrastructure, including reactors, cooling systems, and waste storage facilities. Utilizing underground spaces allows for more efficient use of the available land, minimizing the plant's footprint and preserving surface areas for other purposes. This is particularly important in densely populated regions or areas with limited land availability.
Environmental Benefits
Underground construction can also offer environmental benefits. By placing facilities below ground, nuclear plants can reduce their visual impact on the landscape, preserving natural beauty and minimizing disruption to local ecosystems. Additionally, underground spaces can provide better insulation and temperature control, enhancing the efficiency of cooling systems and reducing energy consumption.
Waste Management
Effective management of nuclear waste is a critical aspect of nuclear power plant operations. Tunnels and underground storage facilities are essential for safely containing and isolating radioactive waste. Deep geological repositories, for example, are designed to store high-level waste securely for thousands of years, preventing contamination of the environment and protecting public health.
Benefits of Using Tunnels in Cooling Water Systems
Cooling water systems are vital for the operation of nuclear power plants, as they dissipate the heat generated by nuclear reactors. The use of tunnels in these systems offers several significant benefits:
Enhanced Efficiency
Tunnels can facilitate the efficient transport of cooling water from natural sources, such as oceans or rivers, to the nuclear plant. By utilizing tunnels, plants can minimize the distance and resistance that water must travel, reducing energy consumption and improving overall cooling efficiency. This is particularly beneficial for large-scale plants that require substantial volumes of cooling water.
Environmental Protection
Using tunnels for cooling water intake and discharge helps protect the environment. Tunnels can be designed to minimize the impact on marine and freshwater ecosystems by carefully locating intake and discharge points. This approach reduces the risk of thermal pollution and protects aquatic life from the adverse effects of temperature changes and water flow disruptions.
Picture courtesy wikipedia: Hinkley Point C Nuclear Power Plant, UK
Security and Reliability
Tunnels provide a secure and reliable means of transporting cooling water. By placing these systems underground, nuclear plants can protect them from external threats, such as natural disasters and human interference. This enhances the reliability of the cooling system, ensuring continuous and safe operation of the plant.
Cost-Effectiveness
While the initial construction of tunnels may involve significant investment, the long-term benefits often outweigh the costs. Tunnels can reduce maintenance requirements and operational costs by providing a stable and protected environment for cooling water systems. This cost-effectiveness is particularly important for the sustainable operation of nuclear power plants.
Case Studies
Hinkley Point C Nuclear Power Plant, UK
Hinkley Point C, located in Somerset, England, is the first nuclear power station constructed in the UK in over 30 years. This plant is designed to provide low-carbon electricity for around six million homes. The construction of Hinkley Point C involves extensive use of underground spaces, including tunnels for electrical and cooling systems. These subterranean structures enhance the plant's safety by providing protection against natural disasters and potential security threats.
Olkiluoto Nuclear Power Plant, Finland
The Olkiluoto Nuclear Power Plant in Finland is renowned for its innovative use of underground spaces. The plant's spent fuel is stored in deep geological repositories, located hundreds of meters below the surface. These repositories are designed to isolate radioactive waste from the environment for millennia, ensuring long-term safety and sustainability.
Picture courtesy wikipedia: Barakah Nuclear Power Plant, UAE
Barakah Nuclear Power Plant, UAE
The Barakah Nuclear Power Plant in the United Arab Emirates is another example of effective underground space utilization. The plant's design includes extensive underground tunnels and chambers to house critical infrastructure and enhance safety. These subterranean structures provide robust protection against natural disasters and potential security threats, ensuring the plant's reliable operation.
Kudankulam Nuclear Power Plant, India
The Kudankulam Nuclear Power Plant in Tamil Nadu is one of India's largest nuclear facilities. It incorporates extensive underground structures to enhance safety and efficiency. The plant's reactors and associated systems are housed in robust underground chambers, providing protection against seismic activity and potential external threats. Additionally, the plant utilizes underground tunnels for the safe transport and storage of nuclear waste.
Picture courtesy wikipedia: Kudankulam Nuclear Power Plant, India
Conclusion
As India and other countries continue to expand their nuclear capacity, the innovative use of underground spaces will play a crucial role in ensuring the safe and sustainable operation of nuclear power plants, contributing to a cleaner and more secure energy future. By leveraging these subterranean structures, nuclear facilities can enhance their resilience against natural and human threats, optimize land use, and minimize their environmental impact.
No doubt, nuclear power plants are associated with high risks during operation, but the benefits outweigh the risks, which can be mitigated with proper planning, design, construction, and operations.
It can be concluded that underground spaces are not just structural solutions—they’re strategic enablers that elevate the safety, resilience, and sustainability of nuclear power plants in a rapidly evolving energy ecosystem. And the use of underground space and tunnels is vital for ensuring the mitigation of risks and sustainable operation of nuclear power plants.
